UPDATE: 3.20pm

All lanes have now reopened at junction 28 (Tredegar Park) of the M4 after the horses in the stalled box were safely transferred to another vehicle.

Traffic remains slow in the area, and is tailed back two miles eastbound - to the A48(M) junction - and several miles westbound, towards Magor (junction 23).

THE M4 is currently closed in both directions at junction 28 (Tredegar Park) in Newport because of a stalled horsebox.

A detour is operating via the exit and entry slip roads at the junction, while the animals are transferred to a replacement vehicle.

Traffic is currently at a standstill in the immediate vicinity on each side of the junction.

South Wales Argus:

Traffic westbound between junctions 26 (Malpas) and 27 (High Cross) - Picture - Traffic Wales

Tailbacks are longest westbound, currently stretching back several miles towards junction 23 (Magor).